The movement of grain and other materials between various storage spaces, such as silos or bins to a plurality of vehicles or other methods for transporting the grain, such as barges or trucks requires a means of conveying material from the bin to the barge, from the truck to the barge or from the barge to the bins. This conveying mechanism may be a belt conveyor or it may use paddles depending on the nature of the materials being moved and the distance to be moved.
Much of the material, which is subject to being moved by this conveying equipment contains a certain amount of dust. This dust varies in amount, is related to the amount and type of material and is most prevalent when the material is disturbed, such as during transport. This dust quite often becomes airborne during the transport and/or the dumping from the transport into the bin, silo or barge. This dust in many instances may explode when it has not been controlled properly. Grain elevators particularly have exploded and fire may result in a conveyor which has an excessive amount of dust retained in the atmosphere. The reason for the explosion being the ignition of the dust accumulated in areas outside the mass of the material. If the dust is retained within the body of the stored material, explosions or fires do not normally happen.
For these reasons among others, it is important to reduce or contain the dust generated or released during the movement of the material. This dust results from disturbing of the stable mass by the movement of the grain or material in the conveyor, which movement releases the dust normally held in the mass. In an enclosed conveyor this dust also has gotten into the bearings of the conveyor. This resulted in increased wear on the bearings supporting the belts and generates heat which could ignite the dust. This wear also may require new bearings and at the very least will increase the power required to move the material.
Originally, most conveyors, including belt conveyors, were open to the atmosphere and did not contain the dust, therefore fires did not occur. Then the conveyors were enclosed and the dust released from the material was further agitated by the fan-like action of the support spokes for the ends of the rollers. Thus the rollers, which support the belts have caused problems once the conveyors were enclosed to prevent dust pollution of the atmosphere.
The dust within the enclosed conveyor became turbulent due to the movement of air caused by the fan-like spokes on the rollers. The rollers became unbalanced as the accumulation of grain dust inside the rollers and on surfaces inside the cone caused uneven wear and unbalanced forces, thus absorbing more energy. Any change in the alignment of the rollers or the rotation of the rollers results in the flow pattern of the belt being changed, thus also causing a reduction in the efficiency of the conveyor.
Once the entire conveyor was enclosed, in order to retain the dust, the bearings were inside the enclosure in the dust making it difficult to service, adjust or replace the bearings.